JP2009192915A - Lens, light source unit, backlight apparatus and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens capable of reducing luminance unevenness or color unevenness by efficiently subjecting light rays from a light source to color mixture, and to provide a light source unit, a backlight apparatus and a display device. <P>SOLUTION: The lens 1 has an incident side surface 1a which is concave, a light guide part 1b through which light made incident from the incident side surface 1a passes, and an emitting side surface 1c from which the light is emitted. The incident side surface 1a, the light guide part 1b and the emitting side surface 1c are provided in substantially fixed shape in a length direction of the lens 1. The incident side surface 1a has a plane part 1d opposed to the block of an LED 7. A portion having an optical function for scattering or diffusing light from the LED block 3 is provided on the plane part 1d. Thus, the light advancing from the LED block 3 in a perpendicular direction (z-axis direction) or its approximate direction is scattered or diffused. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to, for example, a backlight device used in a display device, a lens used in the backlight device, a light source unit, and a display device equipped with the backlight device.

  Currently, backlights with a high color gamut used in liquid crystal panels use independent LEDs (Light Emitting Diodes) for RGB (Red, Green, Blue), so that more than 100% of the NTSC (National Television System Committee) The ratio is achieved. Therefore, commercialization of PCs (Personal Computers), amusement devices, in-vehicle devices, and even TVs is expected.

  For example, when considering a medium-sized or large-sized backlight of 10 inches or more, both sufficient brightness and thinning are required. Therefore, there is a need for a new design of a direct type LED backlight that has been employed in medium- or large-sized backlights. The direct type LED backlight is a type of backlight in which a plurality of LEDs serving as light sources are arranged two-dimensionally in parallel with the plane of the liquid crystal panel.

  In the case of a direct type LED backlight, the number of LEDs mounted varies depending on whether a power type LED or a normal LED is used due to the light quantity. When power-type LEDs are used, it is difficult to bring the LED elements independent of each other into RGB due to the number, size, and thermal problems. That is, since the distance between the LED elements is increased, it is disadvantageous for RGB light mixing within a limited space. In this case, there is little problem as long as a sufficient optical distance (thickness) can be ensured. However, at present, where thinning is attracting attention, it is still difficult to make the LED elements close to each other, resulting in color unevenness. To do.

  In order to reduce the thickness of the liquid crystal panel, a conventional side emitting type power LED may be used. However, this case also has a limit from the viewpoint of color unevenness.

  On the other hand, if a normal low power LED is used, the distance between RGB elements can be reduced. However, no matter how small the distance is, if the LED element is simply used as it is, it is inevitable that color unevenness directly above the LED will be generated in a backlight premised on thinning. In addition, when the RGB light distribution characteristics of the LED elements are greatly different, it is a big problem that color unevenness is promoted.

  In order to solve such a problem of color unevenness, for example, a plurality of point light sources arranged in a one-dimensional manner, and a cylindrical lens having a long shape in the one-dimensional direction provided on the plurality of point light sources, (For example, refer to Patent Document 1). The cylindrical lens used in this device has a concave lens function (52) in the direction perpendicular to the substrate holding the point light source (y direction). The cylindrical lens also has a convex lens function (54) in a part of the horizontal direction (x direction). It is described that with such a configuration, even if there is no light guide plate, light from a point light source spreads in a planar shape and color unevenness is prevented.

JP 2006-286608 A (paragraphs [0007], [0009], FIG. 5)

  The cylindrical lens in Patent Document 1 diffuses light from a point light source by a concave lens function (52). However, in order to realize a thin display panel and reduce luminance unevenness or color unevenness, further ingenuity is required.

  In view of the circumstances as described above, an object of the present invention is to provide a lens, a light source unit, a backlight device, and a display device that can efficiently mix light from a light source and reduce luminance unevenness or color unevenness. It is in.

  In order to achieve the above object, a lens according to the present invention is a lens that diffuses light emitted from a light source, and is provided on the flat part facing the light source and the flat part, and scatters the light. Or an optical function unit that diffuses, a concave incident side surface on which the light emitted from the light source is incident, a light guide unit through which the light incident from the incident side surface passes, and the light guide unit And an exit side surface for emitting the light passing therethrough.

  For example, when there is no lens according to the present invention, light incident on an optical sheet such as a general light guide plate or a diffusion sheet from a light source generates a portion having a high luminance immediately above the light source. That is, luminance unevenness or color unevenness occurs. In the present invention, the light incident on the plane portion is scattered or diffused by the optical function portion provided on the plane portion of the incident side surface. Therefore, luminance unevenness or color unevenness can be reduced. In addition, the provision of the optical function unit on the flat surface facilitates processing and processing applied to the lens for such scattering or diffusion during the manufacture of the lens.

  One or more light sources are provided. As the light source, an element that emits light by an EL (Electro Luminescence) phenomenon, a cathode tube, or another light emitting element is used. As an element that emits light by an EL phenomenon, there is an LED which is a dispersion type EL element or an intrinsic EL element.

  One light source includes one or more light emitting elements. When one light source has one light emitting element, the light color of the light emitting element may be anything. When there are a plurality of light emitting elements possessed by one light source, these colors may be a single color or a plurality of colors (a combination of colors can be changed as appropriate). For example, when the light emitting element is an LED, a plurality of LEDs may be realized in one package. In this case, one light source may correspond to one or a plurality of packages.

  In the present invention, luminance unevenness is reduced when one light source is a single color, and luminance unevenness and color unevenness are reduced when one light source has two or more colors. Hereinafter, at least one of luminance unevenness and color unevenness is simply referred to as light unevenness.

  The higher the degree of light “scattering” by the optical function unit, that is, the smaller the number of light rays that are scattered and travel in the direction perpendicular to the plane portion, the greater the rate of light reflection (or absorption).

  For example, the light source is a plurality of light emitting elements that are arranged in a predetermined direction and emits light by an EL phenomenon, and the lens has a shape that is long in the predetermined direction. In this case, the lens may have substantially the same light distribution characteristic in a direction orthogonal to the predetermined direction within a plane where the plurality of light emitting elements are arranged.

  The optical function unit is a part subjected to printing processing or roughening processing. Thereby, light is scattered or diffused. In addition, the amount of light passing through the flat portion can be adjusted by the printing process.

  The “roughening process” includes a flat part formed in a prism shape, a dot process, a blast process, or the like.

  Since the “printing process” has an effect of scattering light microscopically, the “printing process” can be included in the concept of the “roughened” part.

  The emission side surface has a printed portion facing the flat portion. Since the printing process is performed on both the flat portion and the surface facing the flat portion, the effect of scattering light is promoted and light unevenness is reduced. Alternatively, the emission side surface has a roughened portion facing the flat surface portion.

  For example, the emission side surface is a cylindrical surface or a toroidal surface.

  The lens may further include a bottom surface and a print processing unit or a roughening processing unit provided on the bottom surface. Alternatively, a reflecting material, a reflecting film, or the like may be formed on the bottom surface of the lens. Thereby, the light ray in a light guide part can be increased and high brightness | luminance can be implement | achieved. “Reflection” is not limited to the case where 100% of light is reflected, but includes the case where part of the light is transmitted through the bottom surface.

  The light guide unit may include a diffusing material. Thereby, the light from a light source can be diffused efficiently.

  The lens further includes a heat flow path that is provided from the incident side surface to the emission side surface and that releases heat generated from the light source. Thereby, the heat generated from the light source can be released to the outside of the lens.

  The heat flow path may be provided from the flat portion to the emission side surface, or may be provided from a portion other than the flat portion to the emission side surface.

  The heat flow path may be a through-hole formed in the lens, or may be made of a material having higher thermal conductivity than the main material of the lens.

  The light source unit according to the present invention includes a light source and a lens that diffuses the light emitted from the light source. The lens described above may be used as the lens.

  The light source unit further includes an optical member mounted on the light source for scattering or diffusing the light. As a result, light unevenness is reduced. For example, when a light emitting element having a single color or a plurality of colors is used as the light source, the light distribution characteristics of a specific color can be improved. That is, light of a specific color from the light source can be directed in a desired direction and incident on the incident side surface of the lens.

  The optical member includes, for example, a sheet material. As the sheet material, a prism sheet, a diffusion sheet, or the like is used. Alternatively, a sheet material whose surface is subjected to dot treatment or blast treatment may be used.

  The light source includes a light emitting element that emits light by an EL phenomenon, and the optical member includes a sealing material that seals the light emitting element. Since the sealing material also has a function of scattering or diffusing light from the light source, light unevenness can be reduced and the light source unit can be made thinner.

  The sealing material may include a diffusing material.

  The light source unit further includes a common substrate, the light source includes a plurality of the light emitting elements mounted side by side on the common substrate, and the sealing material seals the plurality of light emitting elements, respectively. To do. That is, the light source unit has a so-called potting type light source block.

  The backlight device according to the present invention includes the light source unit and a support member that supports the light source unit.

  A display device according to the present invention includes the backlight device and a light transmittance control panel that includes a plurality of pixels and variably controls the transmittance of the light emitted from the backlight device for each pixel. It has. A typical example of the light transmittance control panel is a liquid crystal panel. However, any panel that controls the light transmittance of the backlight for each pixel may be used.

  As described above, according to the present invention, the light from the light source can be mixed efficiently and the luminance unevenness or color unevenness can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing a backlight device according to an embodiment of the present invention.

  The backlight device 10 includes a plurality of light source units 5 and a support member 2 that supports these light source units 5. The backlight device 10 is applied to a display device using a light transmittance control panel (not shown). A typical example of the light transmittance control panel is a liquid crystal panel. However, any panel can be used as long as the light transmittance of the backlight is variably controlled for each pixel.

  When the backlight device 10 is applied to the display device, an optical sheet such as a diffusion sheet or a prism sheet (not shown) may be disposed between the backlight device 10 and the light transmittance control panel.

  Examples of the support member 2 include a substrate shape and a frame shape, or an assembly in which two or more members are combined. The material of the support member 2 is made of resin, metal or the like, but is not limited thereto. In order to diffuse the heat generated from the light source unit 5, the support member 2 may be made of a material having high thermal conductivity such as copper, aluminum, or carbon.

  A plurality of light source units 5 are arranged in one direction, for example, the horizontal direction (x-axis direction) in FIG. By arranging a plurality of line-shaped light sources 15 arranged in the vertical direction (y-axis direction), a plurality of light source units 5 are arranged in a planar shape. In the example of FIG. 1, the line light source 15 for one line includes twelve light source units 5, and one backlight device 10 includes the line light source 15 for six lines. The number, arrangement, size and the like of the light source unit 5 and the line light source 15 can be changed as appropriate.

  As shown in FIG. 1, one light source unit 5 includes a plurality of (six in the example of FIG. 1) LED blocks 3 mounted on a base material 4, and a lens 1 that diffuses light from these LED blocks 3. With. One LED block 3 is configured by packaging a plurality of LEDs 7. One LED block 3 includes one or a plurality of LEDs 7 (see FIG. 3). However, one light source unit 5 may include one LED block 3. The pitch of each LED block 3 is several mm to several tens mm, but is not limited to this range.

  FIG. 2 is a perspective view showing a part of the line light source 15. Thus, the line light source 15 is configured by arranging a plurality of light source units 5. In the example of FIG. 2, there is no space between the light source units 5, but there may be a predetermined distance between the light source units 5. A power supply lead wire 6 is connected to the back side of each base material 4 of the line light source 15.

  When one LED block 3 includes one LED 7, the color of light emitted by the one LED 7 is a single color (white, red, green, blue, or other colors). The LEDs 7 of these multiple colors are arranged in order.

  FIG. 3 is a plan view showing the LED block 3 according to the present embodiment. As described above, the LED block 3 includes the RGB three-color LEDs 7R, 7G, and 7B and members such as the substrate and the reflector 8 that support these LEDs. The LEDs 7R, 7G, and 7B are provided so as to be aligned in the x-axis direction.

  The reflector 8 has a recess 8a, and the LED 7 is disposed in the recess 8a. The reflector 8 is made of a material having high reflectivity (that is, zero-order diffraction), such as aluminum nitride. However, the reflector 8 may be aluminum, copper, iron, stainless steel, or may be a material other than these. Alternatively, the reflector 8 may be made of a highly heat conductive material such as a carbon resin or a metal other than the above. Thereby, accumulation of heat in the LED block 3 is reduced, and a large current can be applied to the LED 7.

  FIG. 4 is a sectional view of one light source unit 5 (a sectional view taken along line AA in FIG. 1). FIG. 5 is a perspective view seen from the bottom side of the lens 1.

  The lens 1 has a long shape in a predetermined direction, for example, the x-axis direction, according to the number of LED blocks 3 in one light source unit 5. When the LED block 3 is one, the lens 1 may have a long shape in the y-axis direction. The length of the lens 1 in the x-axis direction is about several tens of mm, but is not limited thereto and can be changed as appropriate. The length of the lens 1 in the y-axis direction is about several mm to several tens mm, but is not limited to this and can be changed as appropriate.

  The lens 1 has a shape that is long in the x-axis direction, and has substantially the same light distribution characteristics in the y-axis direction orthogonal to the x-axis direction within a plane on which the plurality of LEDs 7 are arranged.

  For example, the lens 1 includes a concave incident side surface 1a, a light guide portion 1b through which light incident from the incident side surface 1a passes, and an output side surface 1c that emits light. The incident side surface 1 a, the light guide portion 1 b, and the emission side surface 1 c are provided in a substantially constant shape in the length direction of the lens 1. A plurality of LED blocks 3 are arranged along the length direction of the lens 1 so that each LED 7 emits light into the recess formed by the incident side surface 1a. The exit side surface 1c of the lens 1 includes, for example, a cylindrical surface (that is, a part of a spherical surface as viewed in the xz plane in FIG. 4). In addition, the emission side surface 1c may be a toroidal surface, a combination of a cylindrical surface and a flat surface, a combination of a toroidal surface and a flat surface, or other aspherical surfaces. In the case of a lens having a toroidal surface, a lens having a radius, a conic coefficient, or an aspheric coefficient set for each chip size of the plurality of LEDs 7 may be used.

  The incident side surface 1 a has a flat portion 1 d that faces the block of the LED 7. The flat portion 1d is provided with a portion having an optical function of scattering or diffusing light from the LED block 3. For example, as shown in FIG. 5, in the present embodiment, the plane processing unit 1 d is provided with a print processing unit 12 that has been subjected to print processing. At the time of this printing process, for example, the flat portion 1d is printed in white or a color close to white, and the amount of light transmitted through the flat portion 1d can be adjusted according to the printing state. The color of the printing process is not limited to white or a color close to white, and may be other colors as long as light can be scattered at least.

  As the degree of “scattering” of light on the flat surface portion 1d increases, that is, as the number of light beams that are scattered and travel in the direction perpendicular to the flat surface portion 1d (z-axis direction) decreases, the reflection (or absorption) of light is reduced. The rate can be large.

  As a material of the lens 1, glass, polycarbonate, olefin, or other resin is used.

  The operation of the light source unit 5 configured as described above will be described.

  The light emitted from each LED block 3 enters the incident side surface 1a. Since the incident side surface 1a is concave, the light incident from the incident side surface 1a diffuses and passes through the light guide 1b as shown in FIG. The light that has passed through the light guide portion 1b is emitted from the emission side surface 1c. Since the emission side surface 1c is convex, the light emitted from the emission side surface 1c is further diffused.

  FIG. 6 is a simulation diagram showing a plurality of light rays passing through the lens 1. As can be seen from FIG. 6, the light emitted from the LED block 3 is diffused and emitted from the lens 1 due to the unique shape of the lens 1. FIG. 7 is a simulation diagram showing light rays passing through the lens 1 as seen from the z-axis direction of the lens 1. As can be seen from FIG. 7, in the light guide portion 1b, the light also travels in the length direction of the lens 1 or a direction close thereto. Of the light passing through the light guide portion 1b, the light reflected by the emission side surface 1c travels toward the bottom surface 1e. For example, as described later, when a reflective material or a reflective film is formed on the bottom surface 1e, the light is reflected by the bottom surface 1e.

  In the lens 1 according to the present embodiment, the light traveling from the LED block 3 in the vertical direction (z-axis direction) or a direction close thereto is scattered or diffused by the print processing unit 12 provided immediately above the LED block 3. Is done. Thereby, in the center part (between the plane part 1d and the part of the output side surface opposite to it) in the light guide part 1b of the lens 1, each color is mixed effectively and a brightness nonuniformity and a color nonuniformity are reduced.

  FIG. 8 is a simulation diagram showing light rays from the LED block 3 when the lens 1 according to the present embodiment is not provided. In the case of the lens 1 shown in FIG. 6, it can be seen that there are few light rays emitted from the emission side surface 1 c of the lens 1 in the vertical direction or in a direction close thereto compared to the case of FIG.

  In addition, although the size of the lens 1 is small, by providing a planar portion, the printing process on the planar portion 1d is facilitated.

  In the present embodiment, the number of lenses 1 mounted on one backlight device 10 is reduced by arranging the LED blocks 3 in a line shape in the x-axis direction and providing the long lenses 1 in the x-axis direction. Can do. Therefore, when the backlight device 10 is manufactured, the number of mounting steps of the lens 1 (mounting step of the light source unit 5) can be reduced, leading to cost reduction.

  In the present embodiment, it is not necessary to use an expensive optical member such as a dichroic mirror, so that an inexpensive backlight device 10 and display device can be realized.

  Generally, in order to reduce luminance unevenness, a diffusion sheet or a sheet for reducing luminance unevenness is used. In that case, since the utilization efficiency of light deteriorates, high brightness was maintained as a whole by providing a large number of LEDs 7. However, in this embodiment, since it is not necessary to use such a sheet for reducing luminance unevenness, a desired luminance can be obtained even if the number of LEDs 7 is reduced.

  FIGS. 9A and 9B are simulation diagrams showing light rays from the LED block 3 to the diffusion plate 13 in the case where the lens 1 is not present and in the case where the lens 1 is not present, respectively. These figures are views seen from the x-axis direction. FIG. 10 is a simulation diagram showing light rays when the lens 1 is shown in FIG. 9B, and is a perspective view seen from above the diffusion plate 13. As shown in FIG. 9B, it can be seen that the number of light rays traveling in the oblique direction out of the light rays emitted from the lens 1 is larger than that in the case of FIG. 9A. That is, when the lens 1 is present, luminance unevenness and color unevenness on the diffusion plate 13 are reduced compared to when the lens 1 is not present.

  FIGS. 11A and 11B are diagrams showing the TF (Transfer Function) of the lens in FIGS. 9A and 9B, respectively. In FIGS. 11A and 11B, a graph represented by a solid line indicates the TF in the y-axis direction (see FIG. 4) of the lens. A graph represented by an alternate long and short dash line indicates the TF in the x-axis direction of the lens. In particular, focusing on the TF in the y-axis direction represented by the solid line, when there is no lens 1, the FWHM (Full Width at Half Maximum) is 50 mm or less as shown in FIG. When the lens 1 was present, the FWHM was about 90 mm as shown in FIG.

  As a modification of the lens 1, as shown in FIG. 12, a print processing unit 12 b that has undergone a printing process may also be provided on the bottom surface 21 e of the lens 21. FIG. 13 is an enlarged view of a part of the bottom surface 21e of the lens 21 shown in FIG. The lens 21 is different from the lens 1 in that a print processing unit is also provided on the bottom surface 21 e of the lens 21.

  The print processing unit 12b only needs to have a function of scattering or reflecting light traveling toward the bottom surface 21e out of light passing through the light guide unit 1b. Therefore, the light transmittance in the print processing unit 12b may be different from the light transmittance in the print processing unit 12a in the plane portion 21d. Or both may be the same. For example, the light transmittance of the print processing unit 12b on the bottom surface 21e may be set lower than that of the print processing unit 12a on the flat surface portion 21d.

  Alternatively, a reflective material or a reflective film other than the printing process may be formed on the bottom surfaces 1e and 21e of the lenses 1 and 21. For example, a metal reflective film such as aluminum may be formed on the bottom surfaces 1e and 21e.

  FIG. 14 is a cross-sectional view showing a lens according to another embodiment of the present invention. In the following description, the description of the same structure and function of the light source unit 5 and the lens 1 according to the embodiment shown in FIGS. 1 to 5 will be simplified or omitted, and different points will be mainly described. To do.

  FIG. 14 is a cross-sectional view seen in the x-axis direction, similarly to the case shown in FIG. The lens 31 according to the present embodiment includes a diffusing material 32. By including the diffusing material 32 in the lens 31, light can be diffused efficiently, and luminance unevenness and color unevenness can be reduced. In particular, the effect of making the light passing through the central portion 31f of the lens 31, that is, the portion from the flat surface portion 31d to the portion of the emission side surface 31c facing the flat surface portion 31d uniform, can be obtained.

  The diffusing material 32 is not necessarily included in the entire lens 31. At least, it may be included in the central portion 31f.

  Examples of the diffusing material 32 include the following materials.

  Cross-linked acrylic powder, ultra-fine acrylic powder, cross-linked polystyrene particles, methyl silicone powder, cross-linked styrene particles, monodisperse cross-linked acrylic particles, cross-linked siloxane, silver powder, titanium oxide, calcium carbonate, barium sulfate, aluminum hydroxide, silica Glass, white carbon, talc, mica, magnesium oxide, zinc oxide and the like.

  FIG. 15 is a cross-sectional view showing a lens according to still another embodiment of the present invention. A roughening processing portion 44 that has been subjected to roughening processing is provided at the central portion (planar portion 41 d) of the incident side surface 41 a of the lens 41. A similar roughening processing unit 46 is also provided on the exit side surface 41 c of the lens 41. The roughening processing units 44 and 46 may be, for example, a part formed in a prism shape, or may be a part subjected to dot processing or blast processing. The roughening processing units 44 and 46 may be formed by different processes (prisms, dots, blasting, etc.).

  FIG. 16 is a cross-sectional view showing a lens according to still another embodiment of the present invention. Roughening processing portions 54, 56, and 52 are provided on the central portion (planar portion 51d) of the incident side surface 51a of the lens 51, the portion 51g on the exit side surface that faces the planar portion 51d, and the bottom surface 51e, respectively. Yes. The roughening processing units 54, 56, and 52 are the same as those described in the embodiment in FIG.

  FIG. 17 is a cross-sectional view showing a lens according to still another embodiment of the present invention. Print processing units 64 and 66 are respectively provided in the central portion (planar portion 61d) of the incident side surface 61a of the lens 61 and the portion 61g on the exit side surface facing the planar portion 61d. The print processing units 64 and 66 are the same as the print processing unit 12 in the embodiment shown in FIGS.

  FIG. 18 is a cross-sectional view showing a light source unit according to still another embodiment of the present invention. An optical member 26 that scatters or diffuses light from the LED block is mounted on the LED block 3 of the light source unit 25. The surface of the optical member 26 (the surface from which the light from the LED 7 is emitted) is subjected to roughening processing such as prism processing, dot processing, and blast processing described above.

  For example, the optical member 26 may be used as a sealing material that seals the LED 7 (for example, a member that seals the concave portion 8a of the reflector 8). Thereby, since the sealing material also has a function of scattering or diffusing light from the LED 7, luminance unevenness and color unevenness can be reduced, and the light source unit 25 can be made thinner. For example, by using an optical member 26 that has been subjected to prism processing, it is possible to prevent a specific color of RGB and / or other colors from proceeding in the vertical direction or a direction close thereto. Thereby, a light distribution characteristic can be improved.

  As a material of the optical member 26, for example, silicone transparent resin, olefin resin, other resin, and glass are used. The optical member 26 may include the various diffusing materials described above.

  In addition, the surface of the reflector 8 of the LED block 3 (for example, the surface of the recess 8a) may be subjected to the above roughening treatment.

  As described above, at least two of the characteristic parts of the lenses 1, 21, 31, 41, 51, 61 and the light source unit 25 shown in FIG. 1 (and FIGS. 2 to 5) and FIGS. It is also possible to realize a lens configured as described above. FIG. 19 is a diagram illustrating a light source unit according to an embodiment of the combination embodiment, for example. In the light source unit 35, print processing portions 74 and 72 are provided on the flat surface portion 71d and the bottom surface portion 71e of the lens 71, respectively. The lens 71 includes a diffusing material 32, and an optical member 26 (for example, a prism sheet) is mounted on the LED block 3.

  Of the emission side surface 71c of the lens 71, a portion 71g facing the flat portion 71d may be formed in a flat surface.

  FIG. 20 is a photograph showing the light source unit 35 shown in FIG. 19 in which light emitted from one light source unit 35 provided with, for example, six LED blocks 3 is diffused by the diffusion plate. . In this example, a FWHM of 95 mm was obtained for the TF on the diffusion plate. The present inventor conducted a similar experiment with a light source unit having no lens, and found that the FWHM was 42 mm.

  FIG. 21 is a cross-sectional view showing a lens according to still another embodiment. In the center of the lens 81, a heat flow path 81h that is provided from the incident side surface 81a to the output side surface 81c and that emits heat generated from the LED block 3 is provided. Thereby, the heat generated from the LED block 3 can be released to the outside of the lens.

  The heat flow path 81 h is typically a through hole that penetrates the lens 81. However, the heat channel 81h may be made of a material having higher thermal conductivity than that of the main material of the lens 81, such as a metal or carbon. The number, size, shape, arrangement, and the like of the heat flow path 81h can be changed as appropriate.

  The lens 81 shown in FIG. 21 is a lens in which the print processing unit 84 is provided on the flat surface portion 81d. However, the heat flow path 81 h may be provided in the lenses 21, 31, 41, 51, 61, 71 shown in the above embodiments.

  FIG. 22A to FIG. 22D are diagrams showing LED blocks according to other embodiments, respectively.

  The LED block 23 shown in FIG. 22A includes an LED 7R, two LEDs 7G, and an LED 7B. Of the four LEDs 7, for example, two LEDs 7G arranged at both ends emit green light. The light source unit including the LED block 23 typically includes a plurality of LED blocks 23 arranged in the direction (x-axis direction) in which the LEDs 7 are arranged, and has a lens having a long shape in the x-axis direction.

  Of the three LEDs 7 of the LED block 33 shown in FIG. 22B, the LED 7G arranged at the center is larger than the others. That is, the LED has a larger light emitting area than the others. Although the concave portion 18a of the reflector 18 has an oval shape, it may of course have a circular shape.

  In the LED block 43 shown in FIG. 22C, the concave portion 28 a of the reflector 28 is provided in each of the four LEDs 7. Of the four LEDs 7, for example, the LEDs 7G at both ends emit green light.

  The LED block 53 shown in FIG. 22D includes a reflector 38 having a quadrangular (for example, rectangular, square, etc.) concave portion 38a.

  The lenses of the light source unit on which the LED blocks 23, 33, 43, 53 shown in FIGS. 22A to 22D are mounted are the lenses 1, 21, 31, 41, 51 shown in the above embodiments. 61, 71, 81, or a lens in which at least two of the characteristic portions of these lenses are combined may be employed.

  FIG. 23 is a cross-sectional view showing a light source unit according to still another embodiment of the present invention.

  The LED block 63 of the light source unit 45 is a potting type LED block. FIG. 24A is a perspective view showing the LED block 63, and FIG. 24B is a plan view thereof. The potting type LED block 63 is configured by sealing a plurality of LEDs 7 mounted in a line on a common substrate 68.

  The sealing material 36 is made of a transparent resin, glass, or the like, and has, for example, a shape of a part of a sphere, that is, a lens function. The shape of a part of the sphere is typically a hemispherical shape, but is not limited thereto. Moreover, even if it is not a sphere, a toroidal surface and a quadratic or higher-order curved surface may be sufficient. The sealing material 36 may be the same as the material of the optical member 26 or may be different. As each LED 7, typically, an LED 7G is disposed at both ends, and two LEDs 7R and 7B are disposed at the center. The color scheme, arrangement, number, and the like of each LED 7 can be changed as appropriate.

  FIG. 25 is a plan view showing a state in which the plurality of LED blocks 63 configured as described above are arranged inside the incident side surface 100 a of the lens 100. As shown in FIG. 25, one light source unit 45 typically includes a plurality of LED blocks 63 and one lens 100. The number of LED blocks 63 included in one light source unit 45 can be changed as appropriate.

  As the lens 100, the lens 1, 21, 31, 41, 51, 61, 71, 81 shown in each of the above embodiments, or a lens in which at least two of the characteristic portions of these lenses are combined is adopted. That's fine.

  The sizes a, b, and c shown in FIGS. 24B and 25 are a = 2 to 4 mm, b = 9 to 12 mm, and c = 9 to 15 mm, respectively. However, of course, a, b, and c are not limited to these sizes.

  By using such a potting type LED block 63, as shown in FIG. 23, for example, the light distribution of red (R) and green (G) (blue (B)) becomes substantially the same, Color mixing is promoted with respect to the diffusion plate. Thereby, color unevenness is reduced. FIG. 26 is a diagram illustrating the light distribution characteristics of each color of RGB by the LED block 63. As shown in FIG. 26, a light distribution in which each color of RGB is close to Lambertian (uniform diffusion) is realized.

  Particularly, since the sealing material 36 of the LED block 63 has a shape of a part of a sphere, multiple reflection due to total reflection is small, and high light extraction efficiency can be realized. Further, since the sealing material 36 has a shape of a part of the sphere, when one LED is viewed macroscopically, it becomes close to a point light source, and the function of the lens can be exhibited to the maximum.

  FIG. 27A is a perspective view showing a light source block according to still another embodiment of the present invention. FIG. 27B is a plan view thereof.

  The LED block 73 includes a plurality of LEDs 7 arranged close to each other, a case 99 for packaging each LED 7, and a sealing material 47 for sealing each LED 7. 27A and 27B, LEDs 7G, 7R, 7B, and 7G are arranged from the left side. The color scheme, arrangement, number, and the like of each LED 7 can be changed as appropriate. The sealing material 47 is made of a transparent resin, glass, or the like, and has an upper surface that is flat, and has no lens function. However, the shape may be designed so that the sealing material 47 has the function of a lens.

  As shown in FIG. 27B, the horizontal size d of the case 99 is d = 6 to 9 mm, but is not limited to this range.

  FIG. 28 is a plan view of the light source unit showing a state in which a plurality of LED blocks 73 are arranged inside the incident side surface 100a of the lens 100 for the same purpose as the light source unit shown in FIG.

  FIG. 29 is a table comparing the LED block 63 shown in FIG. 24 with the LED block 73 shown in FIG.

  Embodiments according to the present invention are not limited to the embodiments described above, and other various embodiments are conceivable.

  The case where the light source unit or the backlight device 10 according to each of the above embodiments is used in a display device has been described. However, the present invention is not limited to the display device, and the light source unit and the backlight device 10 can be applied to commercial and public notice signs.

  As shown in FIGS. 1 and 2, in the above embodiment, the LED blocks 3, 23, 33, 43, and 53 are mounted on the base material, and the base material 4 is attached to the support member 2. However, the LED blocks 3, 23, 33, 43, 53 (or each LED 7) may be directly attached to the support member 2.

  In FIGS. 22A to 22D, the LED blocks 23, 33, 43, and 53 are exemplified by those equipped with the LEDs 7 that emit RGB colors, respectively. However, of course, LED blocks 23, 33, 43, and 53 on which white LEDs are mounted may be applied.

It is a figure which shows the backlight apparatus which concerns on one embodiment of this invention. It is a perspective view which shows a part of line light source. It is a top view which shows the LED block which concerns on this Embodiment. It is sectional drawing (the AA sectional view taken on the line in FIG. 1) of one light source unit. It is the perspective view seen from the bottom face side of a lens. It is a figure of the simulation which shows the several light ray which passes along a lens. It is the figure of the simulation which shows the light ray which passes along the lens seen from the z-axis direction of the lens. It is a figure of the simulation which shows the light ray from an LED block in case there is no lens which concerns on this Embodiment. It is a figure of the simulation which shows the light ray from an LED block to a diffuser board in the case where there is no lens and when there is. It is the figure of simulation which shows the light ray when there exists a lens shown in FIG.9 (B), Comprising: It is the perspective view seen from the diffusion plate. It is a figure which shows TF on the diffusion plate in FIG. 9 (A) and FIG. 9 (B), respectively. It is a figure which shows the modification of the lens shown in FIG.4 and FIG.5. It is the figure which expanded a part of bottom face of the lens shown in FIG. It is sectional drawing which shows the lens which concerns on other embodiment of this invention. It is sectional drawing which shows the lens which concerns on another embodiment of this invention. It is sectional drawing which shows the lens which concerns on another embodiment of this invention. It is sectional drawing which shows the lens which concerns on another embodiment of this invention. It is sectional drawing which shows the light source unit which concerns on another embodiment of this invention. It is sectional drawing which shows the light source unit which concerns on another embodiment of this invention. FIG. 20 is a photograph showing how the light emitted from one light source unit is diffused by the diffusion plate in the light source unit shown in FIG. 19. It is sectional drawing which shows the lens which concerns on another embodiment of this invention. It is a figure which shows each the LED block which concerns on other embodiment. It is sectional drawing which shows the light source unit which concerns on another embodiment of this invention. (A) is a perspective view showing the LED block 63, and (B) is a plan view thereof. It is a top view of the light source unit which shows the state in which the several LED block was arranged in the inside of the entrance side surface of a lens. It is a figure which shows the light distribution characteristic of each RGB color by an LED block. (A) is a perspective view which shows the light source block which concerns on another embodiment of this invention. (B) is a plan view thereof. FIG. 28 is a plan view of a light source unit showing a state in which a plurality of LED blocks shown in FIG. 27 are arranged inside an incident side surface of a lens. It is the table | surface which compared the LED block shown in FIG. 24, and the LED block shown in FIG.

Explanation of symbols

1, 21, 31, 41, 51, 61, 71, 81, 100 ... Lens 1a, 21a, 31a, 41a, 51a, 61a, 71a, 81a, 100a ... Incident side surface 1b, 21b, 31b, 41b, 51b, 61b , 71b, 81b: Light guiding portion 1c, 21c, 31c, 41c, 51c, 61c, 71c, 81c ... Exit side surface 1d, 21d, 31d, 41d, 51d, 61d, 71d, 81d ... Plane portion 1e, 21e, 31e, 41e, 51e, 61e, 71e, 81e ... Bottom 3, 23, 33, 43, 53, 63, 73 ... LED block 5, 25, 35, 45 ... Light source unit 7, 7R, 7G, 7B ... LED
DESCRIPTION OF SYMBOLS 8, 18, 28, ... Reflector 10 ... Backlight apparatus 12, 12b, 12a, 64, 66, 74, 84 ... Print processing part 26 ... Optical member 44, 46, 54, 56 ... Roughening processing part 81h ... Heat flow path 98 ... Common substrate

Claims (19)

A lens that diffuses light emitted from a light source,
A concave incident side surface on which the light emitted from the light source is incident, and having a planar portion facing the light source, and an optical function unit that is provided on the planar portion and scatters or diffuses the light. ,
A light guide through which the light incident from the incident side surface passes;
An exit side surface that emits the light passing through the light guide. The lens according to claim 1,
The optical function unit is a lens that is a printed part. The lens according to claim 2,
The exit surface is a lens having a printed portion facing the flat portion. The lens according to claim 1,
The optical function unit is a lens that is a roughened part. The lens according to claim 4,
The exit surface is a lens having a roughened portion facing the flat portion. The lens according to claim 1,
The exit surface is a lens having a roughened portion facing the flat portion. The lens according to claim 1,
The exit surface is a lens that is a cylindrical surface or a toroidal surface. The lens according to claim 1,
The bottom,
A lens further comprising: a printing processing unit or a roughening processing unit provided on the bottom surface. The lens according to claim 1,
The light guide unit is a lens including the light diffusing material. The lens according to claim 1,
A lens further provided with a heat channel that is provided from the incident side surface to the emission side surface and emits heat generated from the light source. The lens according to claim 1,
The light source is a plurality of light emitting elements arranged in a predetermined direction and emitting light by EL phenomenon,
The lens is a lens having a long shape in the predetermined direction. The lens according to claim 11,
The lens has substantially the same light distribution characteristic in a direction orthogonal to the predetermined direction within a plane on which the plurality of light emitting elements are arranged. A light source;
A concave incident side surface on which the light emitted from the light source is incident, and having a planar portion facing the light source, and an optical function unit that is provided on the planar portion and scatters or diffuses the light. A lens for diffusing the light emitted from the light source, including a light guide portion through which the light incident from the incident side surface passes, and an emission side surface for emitting the light passing through the light guide portion. Light source unit. The light source unit according to claim 13,
A light source unit further comprising an optical member mounted on the light source and scattering or diffusing the light. The light source unit according to claim 14,
The light source has a light emitting element that emits light by an EL phenomenon,
The optical member is a light source unit having a sealing material for sealing the light emitting element. The light source unit according to claim 15,
The optical member is a light source unit including a diffusing material. The light source unit according to claim 15,
Further comprising a common substrate,
The light source has a plurality of the light emitting elements mounted side by side on the common substrate,
The sealing material is a light source unit that seals the plurality of light emitting elements. A light source; a lens that diffuses the light emitted from the light source; and a planar portion that faces the light source, and an optical function unit that is provided on the planar portion and scatters or diffuses the light. A concave incident side surface on which the light emitted from the light source is incident, a light guide portion through which the light incident from the incident side surface passes, and an emission side surface that emits the light passing through the light guide portion. A light source unit having a lens including:
A backlight device comprising: a support member that supports the light source unit. A light source; a lens for diffusing the light emitted from the light source; and a flat surface portion facing the light source, and an optical function portion provided on the flat surface portion for scattering or diffusing the light. A concave incident side surface on which the light emitted from the light source is incident, a light guide portion through which the light incident from the incident side surface passes, and an emission side surface that emits the light passing through the light guide portion. A light source unit having a lens including:
A support member for supporting the light source unit;
A display device comprising: a plurality of pixels, and a light transmittance control panel that controls the transmittance of the light emitted from the lens for each of the pixels.